Sights for bows have evolved dramatically in the last few decades. An early sight provided a track mounted to the bow and allowed for both windage and elevation adjustment of pins movably mounted to the track. Usually a plurality of pins were used and set for different predetermined ranges for the individual bow and archer. These sights provided an advance in the art for archers over earlier sighting methods. One earlier method of aiming included the use of a consistent nock end anchor point and then using the arrow tip as the front sight which was an effective method for skilled archers but not necessarily for occasional archers. Bows have likewise advanced dramatically in the last few decades from the traditional long bow or recurve bow to the so called compound bow. Crossbows have also made similar advances. Attachment of sight devices to a traditional bow such as a long bow or recurve bow posed problems with potential damage to the structural integrity of the bow sometimes causing the bow to fail particularly in laminated bows commonly referred to as fiberglass bows. Bows now have metallic risers that permit the attachment of numerous devices to the bow without risk of damage to the bow or its structural integrity. Such devices include sophisticated arrow rests, lights, sights with lenses, reels, stabilizers and pin sights. A second or rear sight can also be provided and may be mounted to the bow string to help improve accuracy. Modern bows with sights are extremely accurate and sophisticated. The modern bow is complex and can be considered a complex machine.
Bows that are used for hunting are used in highly variable conditions, particularly highly variable conditions of lighting both as to light intensity (e.g., lumens) and “color” (usually expressed in ° K). The original multi-pin sight, while effective, had its drawbacks. A major drawback of such sights was the visibility of the pins in low light and when viewed on certain backgrounds or targets. Much hunting is done in the morning and in evening when light is low in intensity and/or color. Also, on overcast days, light can be sufficiently low to make the pins difficult to see and to see against a dark background as is not uncommon during hunting and also target shooting.
An early attempt to solve the sight pin visibility problem was to paint the tip of the pin with a light colored or luminescent paint usually using a different color for each pin. The plurality of colors on the pins was used to help quickly identify which range the pin was meant for. The next advance in such sights was to provide a low light-output battery-powered light which would be turned on selectively to illuminate the pins. However, this required batteries which could “burn out” or the light bulb could “burn out”. While effective, there were still disadvantages.
The next advance in sights was the use of fiber optics. Typically, such fiber optics were a single fiber polymeric fiber that absorbed light through the side which light would then project out of the ends of the fiber optic element or fiber. No batteries were required and such fiber optic sights have been commonly used for bow sights and other shooting device sights such as, pistol, rifle and shotgun sights. An easy to view dot of light was provided and no batteries were required. Additionally, such fiber optics could be made in a variety of colors which was beneficial for a multi-pin sight, such as that used on a bow, to help quickly provide differentiation as to which range pin was being viewed. However, even these sights had drawbacks. Sometimes, to gather enough light, the fiber optic was made longer than was convenient for use on a small sight. Additionally, the diameter (the fiber optic fiber was typically round in transverse cross-section) of the sighting end of the fiber optic tended to be large in order for the fiber optic to gather enough light to be readily viewable. The size of the sighting end sometimes interfered with viewing of the target.
One major drawback of fiber optic sights is that when the sight is tuned for low light, to provide enough light absorption and projection in a low light condition, the light projection was often too intense during high light conditions. To tune the sight for high light conditions would then mean not enough light was absorbed and projected for low light conditions. Thus, current sight technology presents mutually exclusive design and use criteria.
There is thus a need for an improved fiber optic sight.